Better toilets? Seriously? The toilets in the Shanghai Metro (or in China, in general) are among its worst features. Many are quite dirty and smelly, and most, if not all, lack soap and toilet paper.
Regarding infrastructure, yes it's new in Shanghai, but new != better. For example, the station floors may look shiny in Shanghai, but they become quite slippery on rainy days—a non-issue in Tokyo. Another example is that many trains in Japan have different air conditioning in different cars even within the same train, a subtle but welcome feature for those sensitive to temperatures—no such thing in Shanghai. Lastly, unlike Japan, metros in Shanghai/China still lack public timetables in 2023. A timetable can save you a lot of time by allowing you to plan your trip.
I agree that the integrated metro system in Shanghai is better for travelers.
Regarding infrastructure, yes it's new in Shanghai, but new != better. For example, the station floors may look shiny in Shanghai, but they become quite slippery on rainy days—a non-issue in Tokyo. Another example is that many trains in Japan have different air conditioning in different cars even within the same train, a subtle but welcome feature for those sensitive to temperatures—no such thing in Shanghai. Lastly, unlike Japan, metros in Shanghai/China still lack public timetables in 2023. A timetable can save you a lot of time by allowing you to plan your trip.
I agree that the integrated metro system in Shanghai is better for travelers.